Check....the first lobe on the front of the cam is #1 exhaust. The second lobe is #2 exhaust. The 3rd lobe is #1 intake.
Cam degreeing help me understand!
- Thread starter dartfreak75
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Check....the first lobe on the front of the cam is #1 exhaust. The second lobe is #2 exhaust. The 3rd lobe is #1 intake.
James Clews
Well-Known Member
Where I have gone wrong and it took me a while to wake up to it is I have a degree wheel that is marked in 360 degrees but you have to count backwards from 180 for some measurements!
dartfreak75
Restore it, Dont part it!
I haven't checked it in the overlap stage but I did check it at tdc on the compression sequence and they are both closed and apear to be even. I will roll it over 180 and see what it looks like. The cam has 4 degrees advance built in when installed straight up so im assuming it should be advanced.
dartfreak75
Restore it, Dont part it!
I used the dial indicator similar to the video tmm posted i set it up and got it as close to TDC and possible then backed it off about 5 degrees set the dial went up to .25 then back around the other way to .25 the subtracted the difference. It was about 2 degrees off I moved my wheel 2 degrees and did it again and it was just about perfect
You are learning a lot about engines dartfreak, the knowledge you are gaining will pay dividends in the future.
It's all interesting, and fun learning as you go through the steps. Feeling of accomplishment when you get it right.
It's all interesting, and fun learning as you go through the steps. Feeling of accomplishment when you get it right.
dartfreak75
Restore it, Dont part it!
Thanks man I thought I was until this now I feel completely lost again haha. I don't understand it I can't figure out what I'm doing wrong. And that drives me insane. I worked 12 hours last night and have to work 12 hours again tonight I was up till noon trying to figure it out never did! I will work on it more in the morning. I just keep racking my Brain trying to figure it out. I almost feel that Its me and I missed a step somewhere or doing something wrong in the degree process I just can't figure out what
If you use a positive piston stop, it will help you understand it even more.
Cam degreeing is not an easy task to do first time around, and you don't need to completely understand it here and now. Confusing yes, just consider this your first step in understanding it and you can look into it some more at a later date.
You pretty much have it right now with your single keyway cam, the way you have it timed.
Like yellow rose says: Top Dead Center on #1 on compression stroke, then roll it over 180° and look at the lifter heights, if even then it is Straight Up Timed, just like you want. If one lifter is higher than the other then something is out of whack, advanced or retarded one way or another.
I just like to see first time engine builders use the single keyway timing gear and time it Straight Up just like factory, Not needing the degree wheel.
Using the multi-keyway timing gears and trying to advance your cam another 4° is where you want to start checking things with a degree wheel so it does not end up
way way off.
The degree wheel is a way to check everyone's machine work, making sure both keyways were cut into the right spots on the timing gears and dots in the right places, and that the cam keyways and lobe centers are where they should be for the application. Bringing it all together to give you the events that you want to see take place.
So yeah, you are doing good not to worry.
beanhead
Well-Known Member
Are you certain the wheel is moving exactly as the crankshaft moves and not slipping? Dial indicator probe centered firmly (and straight!) in the lifter cup and reading movement as soon as the lifter moves with no hiccups? Lifter planted firmly on the cam lobe?
If everything checks out--all that's really left that I can think of is the set is marked wrong or you're not reading it at the right spot.
Starting with the wheel at zero, on TDC compression stroke, that valve will be on the back of the lobe, so zero on the dial. It will stay at zero until you come all the way around to approaching TDC on the exhaust stroke (cam sprocket dot at 6:00) and as you get close to TDC that's when the dial should start moving. So! If that's what you're seeing, but it's still off that many degrees at the .050" lift my money's on a mis-marked sprocket...advance the cam a tooth and re-do. Yeah you'll have to start over, but....
Remember it's where the timing ends up that matters, not how the dots are or aren't lined up..
Keep at it!
If everything checks out--all that's really left that I can think of is the set is marked wrong or you're not reading it at the right spot.
Starting with the wheel at zero, on TDC compression stroke, that valve will be on the back of the lobe, so zero on the dial. It will stay at zero until you come all the way around to approaching TDC on the exhaust stroke (cam sprocket dot at 6:00) and as you get close to TDC that's when the dial should start moving. So! If that's what you're seeing, but it's still off that many degrees at the .050" lift my money's on a mis-marked sprocket...advance the cam a tooth and re-do. Yeah you'll have to start over, but....
Remember it's where the timing ends up that matters, not how the dots are or aren't lined up..
Keep at it!
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dartfreak75
Restore it, Dont part it!
Thanks I understand what you are saying something is off on mine then because I'm not getting any lift until I'm past tdc. I can watch the lobe coming around and the lifter is near the base when its at tdc i checked it at over and over again and it doest start getting lift until after tdc. To answer your questions I have the dial on the circle of the lifter and its nice and tight I set it at zero on the heel of the lobe and its constant I have rolled it over probably 50 times or more and it always resets back to zero on the back side of the lobe. And I don't think the setup there is at fault. However it is possible its something in the wheel. Its one of the printed ones that I glued to a piece of cardboard. The I cut cardboard circles to shim between the crank and crank bolt to squish fit it on. It moves with the crankshaft and I am getting repeated tdc readings. That's what is messing with me. If I can get a continuous zero at tdc on both sides how can I be 22 degrees off? If the wheel is at fault.
dartfreak75
Restore it, Dont part it!
Im actually considering buying me some checking springs and try doing it off the valve. Then I can use a piston stop. I'm pretty confident I have my tdc correct tho.
Why do you have to buy anything? I'm lost. You can use a piston stop now. Don't you have the heads off?
Also, what are you using to turn the crankshaft? What type of device and how is the degree wheel mounted? Unless you spent a good bit on a crank socket, I can almost guarantee you that your crank socket is moving on the crank. There aren't but one or two on the market worth a crap.
dartfreak75
Restore it, Dont part it!
Thanks man I appreciate it. I am learning. I am trying to learn and do it right. I'm not gonna quit until I know it's right. That's just how I am lol. I have one of those addictive ocd personalities I can't quit on something until I'm satisfied with it and right now I'm not lol. I really appreciate all of yalls input.
dartfreak75
Restore it, Dont part it!
I have shimmed the wheel in between cardboard disks I cut out and its bolted on with he crank bolt. Its wedged I between the crank and the washer on the bolt. Once again tho if that was the issue how could it be right at tdc every time both ways? I can go Clockwise to TDC and its zero! Go Counter CW to TDC and its still zero. So I don't understand how it could be moving. That was my first thought also! I will try the positive piston stop and set it to TDC that way. I don't think I'm 20 degrees off TDC but I will try it.
dartfreak75
Restore it, Dont part it!
Is the hole in the wheel the same size as the bolt? I've rarely seen "that". But it sounds like if it is, you should be accurate. I would still recommend a piston stop.
dartfreak75
Restore it, Dont part it!
Sorry missed your post earlier im using the one marked intake. The 2nd one on the #1 cylinder
dartfreak75
Restore it, Dont part it!
It is but I made it that way i drilled it out under size so its a pressed fit on the bolt
OK, then you should be ok there. The only other place a discrepancy might be is not using a piston stop. For like the fourth time. lol
dartfreak75
Restore it, Dont part it!
Yes I know I was just saying I'd like to check the lift at the valves as well probably won't until I get my issue now fixed tho.
To me, lift at the valves is really inconsequential because of the pushrod angle. It's gonna be what it's "gonna be".
dartfreak75
Restore it, Dont part it!
But I'm getting constant tdc readings. If the tdc was off it would not be zero both ways. Im not being hard headed here I will try the the stop way I just don't think it's that. The wheel hasn't moved and im still at tdc all the way on both sides of the stroke. If my tdc was 22 degrees off it wouldn't be zero both ways would it?
dartfreak75
Restore it, Dont part it!
For example if I had it zero tdc in the compression stroke then spun it around to where #6 is at the compression stroke and #1 is tdc the wheel should read like 44 degrees if I was 22 off. Because you have to split the difference. If you go one way its is 20 and the other way its 24 than 22 would be true tdc so you move the wheel to 22 then spin it back around and get 22 again then remove the stop 0 is true tdc! Correct?
**** if I know. I've never done it that way. That's way too convoluted. With the piston stop, rotate the engine until it makes contact. Write the number down on the wheel. Rotate the engine the opposite direction. Write that number down. Halfway between those two is TDC. That just removes "ANY" room for error whatsoever.
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